High power lasers have been used successfully in scanning systems for direct production of printing plates and cylinders. The modulation of these lasers has posed severe technical challenges due to the high optical powers involved, combined with demanding requirements for modulation bandwidth, amplitude and beam pointing stability, and beam profile quality. Solutions to these problems are presented for two systems in current production. In both systems, a combination of careful system design and state of the art modulator design and manufacture has been necessary to achieve success in meeting the demanding system specifications.